Acne.
YES, if the HPV virus is on the balls for example a condom wont protect you
No, chlamydia is spread by sharing infected body fluids.
No, you do not have to have skin to skin contact in order to be infected with chickenpox. You can get chickenpox by breathing in the germs from someones sneeze, cough, skin to skin contact, or...
Yes herpes can be passed through skin to skin contact such as rubbing skin.